Boosting the Photocatalytic O ₂ Reduction Reaction for H ₂ O ₂ Production Over CuS Nanosheets Decorated with CdSe Quantum Dots

Abstract Solar O 2 reduction reaction to produce H 2 O 2 facilitates ecofriendly, effective and efficient substitute for the industrial anthraquinone process for H 2 O 2 production. Meanwhile, concerns including rapid charge recombination and inadequate active sites hindered the photocatalytic activity. Accordingly, herein we addressed the above challenges by employing a photocatalyst based on CuS nanosheets loaded with CdSe quantum dots. A photocatalytic H 2 O 2 production of 1838 ± 32 µmol g −1 h −1 was achieved in presence of ethanol as sacrificial agent for CuS/CdSe which is 2.85 times higher than that of pristine CuS nanosheet (645 ± 38 µmol g −1 h −1 ), with 0.09% solar to chemical conversion efficiency. The result obtained from Pl and EIS analysis demonstrated that this higher photocatalytic efficiency facilitated by the loading of CdSe quantum dots on CuS nanosheet. The XPS, Mott‐Schottky analysis, and quenching experiments revealed the detail of charge transfer pathway for photocatalytic H 2 O 2 production. The oxygen reduction reaction proceeds through an indirect single electron route to produce H 2 O 2 , which showed stability up to four cycles. This study contributes to the significant insight about the synergistic impact of heterojunction and surface plasmon resonance effect on photocatalytic activity.